Reusable, sealable container which has a multiple wall construction encasing a cooling/warming material

ABSTRACT

The present invention overcomes the disadvantages of prior thermal storage devices by combining the advantages of a sealed double wall container with a phase change thermal energy storage synthetic chemical which creates a superior portable and reusable cold/hot thermal storage container. The invention provides for a double walled container with a double walled lid. The double walled container, and lid, having thinner internal walls than the exterior walls and the hollow section between the two walls is filled with a phase change thermal energy storage synthetic chemical, and sealed. The double walled container is then pre-cooled at standard refrigerator freezer temperatures and/or heated in a hot water bath or micro-wave oven. The container can be used to store food or other items that need to be maintained cold or hot for longer periods than previously available by use of the standard water and salt based cold or hot storage chemicals.

BACKGROUND OF THE INVENTION

The present invention relates to a double wall container with a lid which houses a synthetic phase change heat transfer fluid between the container outer and inner walls, including the lid, capable of maintaining a cold or hot temperature for a longer period than previously available.

Phase change thermal energy storage synthetic fluid chemicals have been available for some time. An example of a phase change thermal energy chemical is discussed in detail in U.S. Pat. No. 4,711,813. The phase change thermal chemical described in detail in this patent is a crosslinked polyethylene with a straight chain alkyl hydrocarbon therein. Many such phase change thermal storage chemicals have been developed primarily for the medical compress industry.

Portable cold storage systems have been around for a very long time. The primary portable cold storage system in use today comprises of a mixture of water and salt sealed in a plastic block to create a cold pack container. The container is initially frozen and then it used as a thermal absorption pack in close proximity to the item/s that need to be maintained cold. These blocks are short lived and take up a large volume in the insulated container. Other cold storage systems have been developed using both the standard water based soluble chemicals and the phase change thermal energy storage synthetic chemicals. These are comprised of flat plastic packs designed to remain pliable, even after cold exposure, and are wrapped in a cloth and applied directly as a cold compress on a medical injury. One such compress is described in detail in U.S. Pat. No. 4,462,224.

The present invention is an innovative use of two existing technologies to create a superior product. A double walled container having the hollow section filled with a phase change thermal energy storage synthetic chemical. The container is sealed and used as a portable cold or hot storage container which maintains the item/s in the container cold or hot for prolonged period. The container using the phase change thermal energy storage synthetic chemical will remain cold longer than any water based thermal storage system. The clear advantages of this invention is that the volume of the storage container is not minimized by the presence of a freezing block or a hot pack and the phase change thermal energy storage synthetic chemical can be used both for cooling and/or heating and it will perform for a longer continuous period.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages of the prior thermal storage devices by combining the advantages of a sealed double wall container with a phase change thermal energy storage synthetic chemical which creates a superior portable and reusable cold/hot thermal storage container.

According to the invention, there is provided a double walled container with a double walled lid. The double walled container, and lid, having thinner internal walls than the exterior walls and the hollow section between the two walls is filled with a phase change thermal energy storage synthetic chemical, and sealed.

The double walled container is then pre-cooled at standard refrigerator freezer temperatures and/or heated in a hot water bath or micro-wave oven. The container can be used to store food or other items that need to be maintained cold or hot for longer periods than previously available by use of the standard water and salt based cold or hot storage chemicals.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the invention will become apparent from the following drawings.

FIG. 1 is a cut away view of a container, and lid, having an outer wall, a thinner inner wall, and having the space between the two walls filled with the phase change thermal energy storage synthetic chemical.

FIG. 2 is a cut away view of a container, and lid, having an outer wall, an air pocket, a middle wall, and a thinner inner wall, and having the space between the middle wall and the inner wall filled with the phase change thermal energy storage synthetic chemical. In this FIG. the air pocket acts as an extra insulting layer to maintain the desired internal temperature longer.

FIG. 3 is a cut away view of a container, and lid, with multiple isolated compartments within the same container. The container has an outer exterior wall, a thinner inner wall, and having the space between any two walls filled with the phase change thermal energy storage synthetic chemical.

FIG. 4 is a cut away view of a container, and lid, with a divided compartment with in the same container. The container has an outer wall and thinner inner walls, and having the space between the any two walls filled with the phase change thermal energy storage synthetic chemical

DETAILED DESCRIPTION

Referring generally to FIG. 1-4 and more specific to FIG. 1, a container and lid having a double wall, where the outer container wall is thicker than the inner wall and the hollow area between the walls is filled with a phase change thermal energy storage synthetic chemical. The container walls can be manufactured of polymers, metals, or ceramic materials and they can be sealed by heat sealing or glue. The phase change thermal energy synthetic chemical can be a DOWCAL™ a Dow Chemical product. The phase change thermal energy synthetic chemical can be an ethylene glycol, a polypropylene glycol, or any other of the many similar type phase change thermal energy synthetic chemicals available in the market.

Another alternative embodiment is shown in FIG. 2, a container and lid having a three layered wall. The two outer most walls are comprised of a thick outer wall and a thinner inner wall. The space between the outer wall and the inner wall are maintained as an air gap to promote better insulation. The thicker middle wall and the far most internal thinnest wall creates a space between them that is filled with a phase change thermal energy synthetic chemical.

Yet another alternative embodiment is shown in FIG. 3 & 4. They again comprise of the same design as the item in FIG. 1 with an addition of multiple chambers to keep various items in the same container without mixing, however, designs similar to FIG. 2 with the addition of multiple compartments are also possible to increase thermal efficiency.

In practice, the container can be made of any practical size and shape. The size of the chambers can be varied to accommodate common foods or other stuff, i.e. square sandwiches, bottled drinks or loose items.

The container can be pre-cooled or pre-heated by placing the container in a common standard freezer for cooling or heated in a microwave oven or hot water bath.

Various modifications and changes may be made by one skilled in the art and without departing from the spirit of the invention as expressed in the accompanying claims. Hence, all matters shown and described are to be interpreted as illustrative and not in a limiting sense. 

1. A reusable container to be used as an instant cold or hot receptacle for thermal transfer comprising: a. container and lid having a double wall, where the outer container wall is thicker than the inner wall. b. the hollow space between the outer and inner walls is filled with a phase change thermal energy synthetic chemical. c. container and lid having a three layered wall, where the outer wall is thicker than the middle container wall, and the middle wall is thicker than the inner most wall. d. the hollow space between the outer and middle walls is filled with air e. the hollow space between the middle and inner walls is filled with a phase change thermal energy synthetic chemical.
 2. The container recited in claim 1 wherein the phase change thermal energy synthetic chemical is an ethylene glycol or propylene glycol, and any other phase change thermal energy synthetic chemical available in the market.
 3. The container recited in claim 1 may be comprised of multiple isolated chambers.
 4. The container recited in claim 1 may be comprised of multiple isolated layers.
 5. The container recited in claim 1 provides a superior performing cold or hot thermal storage system. 